Record carrier with multiple coupling elements

ABSTRACT

The invention relates to a record carrier ( 1 ) like a CD-RW+ or a DVD supporting an improved handling and, in particular, an improved access control to information stored on the record carrier ( 1 ) by supplying an additional information source. The record carrier ( 1 ) has a first area ( 3 ) for storing a first kind of information and further has multiple second areas ( 4.1, . . . , 4.8 ) each designed for comprising a coupling element to a device for reading and/or writing the record carrier ( 1 ), the distribution of the coupling elements on the record carrier ( 1 ) encoding a third kind of information, e.g. a regional code indicating the geographical regions the record carrier ( 1 ) is valid. Storage media storing information of second kinds may supplement the coupling elements and a coupling element and a storage medium may be integrated into a chip. Making the coupling elements detachable from the record carrier ( 1 ) results in an easy way of modifying the third kind of information on a finished record carrier ( 1 ).

The invention relates to a record carrier, in particular to a recordcarrier storing access-controlled, in particular copy-protected,information. Examples of such record carriers are mainly Audio CDs,CD-ROMs, CD-Rs, CD-RWs, DVDs etc., but the invention is equallyapplicable to other record carriers as well, as e.g. magnetic tapes,diskettes, and hard disks.

Record carriers such as CDs or DVDs are nowadays a mass product usede.g. for distributing audio and video content for entertainment purposesand to supply software and computer games. Moreover, certain kinds ofthese media such as the CD-R and the CD-RW+ are once or several timesrecordable e.g. by using a CD burner. They are therefore also usable forshort-term backup as well as for long-term archiving purposes. Moreover,the increasing storage capacities of these devices extend theirapplicability even further.

On the other hand, the existence of these easy to handle and durablerecordable media in connection with the digital representation 6f themedia contents opened an easy way of taking one-to-one copies ofcopyrighted CDs, which nowadays presents a major commercial problem forthe content industries. Besides this copy-protection problem the largestorage capacities of these record carriers call for methods supportingthe access to and the preferably personalized presentation of theinformation being stored on the record carriers.

Accordingly, several methods for these purposes have been proposed inthe state of the art. These methods range from encrypting the content ofa record carrier and preventing an easy copying of the decryptinginformation to access-control and personalization structures on therecord carriers as well as on the corresponding reading and/or writingdevices for the record carriers. E.g., among others it was proposed touse password protection, to structure the record carrier in differentparts each part possessing its own access rights, and to use uniqueidentifiers for record carriers in connection with a revocation list ofthe identifiers of counterfeit media. In that, the access control and/orpersonalization themselves might be performed by structures on therecord carrier, by the reading and/or writing device for the recordcarrier, or in cooperation between both.

U.S. Pat. No. 6,044,046 A proposes to use a chip being physicallyintegrated within the record carrier as a device carrying theaccess-control and/or personalization structures for the record carrier.This allows downward compatibility with e.g. traditional CDs and rendersthe record carrier with built-in chip as easy to handle as a recordcarrier itself. Furthermore, U.S. Pat No. 6,044,046 A discloses thecommunication interfaces of the chip and of a corresponding device forreading and/or writing the record carrier with built-in chip. Inparticular, a solution is described for allowing the reading and/orwriting device simultaneous access to the record carrier and thebuilt-in chip. For the full description of these and related issues thecontents of U.S. Pat. No. 6,044,046 A are herewith incorporated intothis application by reference.

U.S. Pat. No. 6,044,046 A also mentions the necessity of establishing ahigh enough data transfer rate between the chip and the reading and/orwriting device for enabling a smooth operation of the record carrier inthe reading and/or writing device. If e.g. an optical path is used forcommunicating between the chip and reading and/or writing device thedata bits on this path can only flow when a respective coupling elementon the record carrier is in sight of the corresponding element of thereader/writer. To enable high enough data rates U.S. Pat. No. 6,044,046A therefore proposes to use a large coupling element on the recordcarrier, e.g. a circular one being in continuous sight of thereader/writer's element, and/or to use multiple coupling elementsdistributed over the area of the record carrier seen by thereader/writer's element. Instead of making the coupling element large oruse a multiplicity of them U.S. Pat. No. 6,044,046 A also foresees thepossibility of a single small coupling element being coupled to anappropriate large or a multiplicity of auxiliary elements serving astransmitter and/or receiver.

While the built-in chip concept of U.S. Pat. No. 6,044,046 A offers aquite flexible solution to access control and informationpersonalization of a record carrier such chips and the structure of itscoupling and/or auxiliary elements and their connections are alreadysomewhat complex and might e.g. be regarded as too costly for storingsmall amounts of information as e.g. a regional code encoding in whatgeographical regions a record carrier is valid. Moreover, modifying theaccess-control information after finishing the record carrier, e.g.after acquiring new access rights, requires re-programming of the chip.But, allowing a user to re-program the access rights on the chip at hisor her premises may compromise the copy protection of the recordcarrier.

Therefore, it is an object of the invention to provide a record carrierand a corresponding device for reading and/or writing it that provides asimple and flexible way of encoding small to medium amounts of handlingand, in particular, access-control information for the record carrier. Afurther object of the invention is to allow for a simple way of adding,deleting, and/or changing this information after production of therecord carrier.

These objects are accomplished by a record carrier having a first areafor storing a first kind of information and further having multiplesecond areas each designed for comprising a coupling element to a devicefor reading and/or writing the record carrier, the distribution of thecoupling elements on the record carrier encoding a third kind ofinformation,

and by a device for reading and/or writing such a record carrier,wherein the device is designed for sensing the distribution of thecoupling elements on the record carrier.

Together, the record carrier and the device for reading and/or writingit form a system for handling information and in particular forsupporting access control to information according to the invention.Moreover, the invention provides a method for handling an inventiverecord carrier and in particular for reading and/or writing such arecord carrier, the method comprising the steps of sensing and decodingthe third kind of information, and handling the record carrier independence on the third kind of information, in particular, readingand/or writing all or part of the first kind of information independence on the third kind of information.

Encoding the record carrier's handling information by the distributionof the coupling elements and observing that a coupling element may beimplemented by very simple circuitry as e.g. just a few turns of aninductive coil achieves the object of a simple and cheap embodiment.Employing a large enough number of coupling elements and using theirrelative radial and angular positions on the record carrier for encodingprovides enough capacity for small and medium amounts of handlinginformation. Such information may e.g. comprise a regional codedetermining in which geographical areas the record carrier is valid, anencoding for the standards the record carrier complies to, and anindication which side is up after having inserted the record carrier inthe reader/writer.

Regional codes e.g. are used to restrict the usage of a record carrierto specific regions only, e.g. a DVD might only have been released inthe U.S., thus, readers sold on the European market should not play sucha DVD, which is accomplished letting the reader check the DVD's regionalcode. In general, the readers/writers will use the handling informatione.g. control their access to the record carrier and to displaycorresponding information to the user, e.g. that he inserted the recordcarrier upside down or that this record carrier does not comply to thestandards supported by the reader/writer. Of course, the information ofthe third kind encoded by the distribution of the coupling elements neednot be handling information only but might be any other information,too.

As already said the coupling elements might be extremely simply, theirminimum requirement just being that they are able to indicate theirexistence to the reader/writer. Thus, e.g., if the coupling iselectromagnetic, a coupling element might just be an inductive coil,e.g. a few turns of a wire in a spiral pattern, or, if the coupling isoptical, the coupling element might just consist of some suitablematerial having a different reflectance than the surrounding carriermaterial. Thus, the term coupling element is used here in its mostgeneral sense, and, as compared to its use in U.S. Pat. No. 6,044,046 A,encompasses not only the coupling elements of this document but also theauxiliary elements mentioned there.

In its simplest form there is no need for interconnecting the couplingelements. But, of course, the coupling elements might be interconnectedwith more powerful other building blocks as e.g. storage media storinginformation of a second kind, e.g. decryption information for thepayload data, typically songs and/or videos and/or computer games, beingstored in encrypted form as the information of the first kind on thefirst area of the record carrier. Moreover, a coupling element and astorage medium might be integrated into a chip rendering, or, as in U.S.Pat. No. 6,044,046 A, a chip might be connected to multiple couplingelements. In this last embodiment one arrives at the solution of U.S.Pat. No. 6,044,046 A with the additional feature of distributing thecoupling elements in a deliberate fashion to encode the information ofthe third kind, thereby obtaining the advantage of supplying anadditional source of information without having to spend additionalelements.

Allowing the coupling elements to be attached or detached from thesecond areas provides a simple way of adding, deleting, or replacingsuch elements, thus changing the distribution pattern in a mere“mechanical” way. For that, the coupling elements might e.g. be producedeach on a plastic film, which is simply glued to a correspondinglyprepared position of the record carrier much like a sticker, or, if thecoupling element are provided in a housing, this housing might besnapped into a corresponding pit being milled into a second area, thehousing being fixed by using some spring mechanism. The couplingelements might be traded separately from the record carriers and, incase of chips, might e.g. be programmed or re-programmed using equipmentonly being available in specialty shops, which would yield an additionallevel of security against counterfeiting such chips. Accordingly, theinvention also relates to such coupling elements and in particular tochips being designed to be attached to an inventive record carrier.

In the same way, the invention also encompasses record carriers whosemultiple second areas are devoid of any coupling element or chip butwhich are designed or prepared for having such coupling elements beingattached. Such designs might e.g. consist in pits being milled in thesecond areas, maybe assisted by some spring mechanism, but might equallywell just consist in markings of the second areas on the record carrier,a coupling element being produced on a plastic film, which is simply tobe glued to the marking of a second area much like a sticker. Suchattaching of coupling elements to the second areas of an inventiverecord carrier may further be simplified for a user by arranging severalcoupling elements on a single carrier, e.g. a plastic film, which isattached to the second areas of the record carrier as a single piece.Accordingly, the invention also relates to such carrier devices forcoupling elements.

Embodying an inventive record carrier and its reading and/or writingdevice in a manner that the record carrier's first area can be readand/or written in parallel to sensing the distribution of the couplingelements on the record carrier offers the advantage that the readingand/or writing device can handle the data encoded on the two areasindependently of each other, i.e. the two data streams can be processedwithout disturbing each other. This offers e.g. the possibility tocontinuously check, e.g. at regular or irregular intervals in time, theauthenticity and/or integrity of the record carrier, thus enhancing theaccess control to the record carrier. E.g., assume that the distributionof the coupling elements specifies a regional code. If the reader/writerverifies this regional code only once when the record carrier isinserted in the device a hacker may betray the device by supplying atthis point a faked regional code using specialized hacked equipment.This kind of attack gets much more involved if the reading and/orwriting device verifies the regional code several times at e.g.irregular time intervals.

While a reader/writer may perform the sensing of the distribution of thecoupling elements on the record carrier as well as the decoding of thedistribution's meaning these tasks may as well be distributed betweenseveral devices. E.g. a simple reader/writer to be used as a peripheralto a personal computer may just do the sensing to transfer thedistribution information to the PC where the application program takesthe task of decoding.

Of course, as is obvious to one skilled in the art, one may combine theabove-described measures for obtaining an even improved handling of aninventive record carrier. E.g., one may advantageously use removablechips integrating a coupling element with a storage medium as well as aprocessor. These chips may then be traded as separate devices and alsomay be programmed or re-programmed at specialty shops.

These and further aspects and advantages of the invention will befurther illustrated by the embodiments and, in particular, by thedescription of the attached figures.

FIG. 1 shows diagrammatically an inventive record carrier and aread/write head of an inventive reader/writer.

FIG. 2 shows diagrammatically a distribution of the second areas on twocircles on an inventive record carrier and a read/write head of aninventive reader/writer.

FIG. 1 shows diagrammatically an inventive record carrier 1 in the formof a disk and a read/write head 10 of an inventive reader/writer. Therecord carrier 1 has a central aperture 2 and a track 3. The track 3 isarranged in a spiral or concentric pattern and comprises a first areafor storing information of a first kind, e.g. payload data like songsand/or videos and/or computer games or personal information of a user.Two second areas 4.1 and 4.2 for storing information of a second kind,e.g. access control and/or personalization information, are also presenton the record carrier 1. The second areas 4.1 and 4.2 each comprise achip integrating a storage medium and a coupling element 5.1respectively 5.2, e.g. an inductive coil or an LED and a photodiode, forcommunicating with the corresponding read/write head 10 of a device forreading and/or writing the record carrier 1. For more details on thegeneral structure of the record carrier 1 and its communication meanswith the device for reading and/or writing it reference is again made toU.S. Pat. No. 6,044,046 A.

The distribution of the coupling elements 5.1 and 5.2 on the recordcarrier 1 is given by their radial distances from the central aperture2, i.e. the lengths of the lines 6.1 and 6.2, and by the angle 7 betweenthese two lines 6.1 and 6.2. This information e.g. is sufficient toindicate the orientation of the record carrier 1 as it is inserted intothe reader/writer.

FIG. 2 shows diagrammatically a distribution of six second areas 4.3through 4.8, being equipped with coupling elements not shown in thefigure, on an inventive record carrier 1 and a read/write head 10 of aninventive reader/writer. The second areas 4.3 through 4.8 are arrangedon two concentric circles 20 and 21 centered on the central aperture 2of the record carrier 1, i.e. the second areas 4.3, 4.4, and 4.5 lie onthe inner circle 20 and second areas 4.6, 4.7, and 4.8 on the outercircle 21. Besides their position on the circles 20 or 21, the angularposition of the second areas 4.3 through 4.8 on the record carrier isgiven by the six angles 31 through 36 formed by the connection lines ofthe second areas 4.3 through 4.8 with the central aperture 2.

During a revolution of the record carrier the read/write head 10 of thereader/writer will sense the relative position of the second areas 4.3through 4.8, i.e. their position on the circles 20 or 21 and theirangular positions 31 through 36. For sensing the position on the circlesthe read/write head 10 might e.g. be constructed as being directiondependent. For sensing the angle between two successive second areas,e.g. the angle 31 between the second areas 4.3 and 4.4 if the diskrotates clock-wise, the reader/writer may measure the time between“seeing” area 4.3 and “seeing” area 4.4, i.e. by measuring the time spanbetween the middle points of the time intervals when being in contactwith area 4.3 respectively 4.4. As the revolution speed of the recordcarrier typically will vary over time, of course, these absolute timespans have to be related to the duration of one revolution. Detectingthat a revolution finished can e.g. be performed by giving one secondarea a code allowing it to be identified or by detecting the periodicre-occurrence of the second areas distribution (provided thedistribution pattern avoids any periodicity within one revolution).

Thus, the read/write head 10 is able to sense the second areas'distribution pattern, which encodes a third kind of information as e.g.a regional code indicating in which geographical regions the recordcarrier is valid, and/or which standards the record carrier complies to,and/or if the record carrier has been inserted upside-down. This lasttask of detecting the orientation the record carrier has been insertedcan e.g. also be performed by using two second areas being on a circleat an angle to each other different from 180° and supplying one of itwith a storage medium equipped with an identification code or by usingthree second areas on a circle at non-equal angles to each other.

Instead of using the different radial positions of the second areas,i.e. their locations on circles 20 or 21, for encoding a third kind ofinformation, such position also might be used to support different kindsof readers/writers having their read/write heads at different radialpositions. In this case, only the angular distribution 31 through 36 isused for encoding the third kind of information.

For addressing the multiple second areas in the communication betweenrecord carrier and reader/writer explicit addresses for the second areasmight be used, which are communicated by the second areas at thebeginning of each communication to the reader/writer. Of course, usageof such codes requires the second areas to each comprise a storagemedium for the code. As an alternative, usage of an aperiodic patternavoids this requirement as described above. After one revolution of therecord carrier (or a few revolutions if the above described periodicityrecognition is used) the reader/writer knows the succession of thesecond areas. At this point latest, instead of requiring an explicitaddress sending the reader/writer may identify the second areas simplyby their succession.

1. A record carrier (1) having a first area (3) for storing a first kindof information and further having multiple second areas (4.1, . . . ,4.8) each designed for comprising a coupling element to a device forreading and/or writing the record carrier (1), the distribution of thecoupling elements on the record carrier (1) encoding a third kind ofinformation.
 2. A record carrier (1) as claimed in claim 1,characterized in that the distribution of the coupling elements on therecord carrier (1) encodes a regional code indicating a geographicalregion the record carrier (1) is valid for, and/or which standards therecord carrier (1) complies to, and/or the orientation in which therecord carrier (1) has been inserted into a device for reading and/orwriting the record carrier (1).
 3. A record carrier (1) as claimed inclaim 1, characterized in that at least one of the second areas (4.1, .. . , 4.8) is designed for detaching and/or attaching a coupling elementto it.
 4. A record carrier (1) as claimed in claim 1, characterized inthat at least one of the second areas (4.1, . . . , 4.8) is designed forcomprising a storage medium for storing a second kind of information,the coupling element of the second area (4.1, . . . , 4.8) serving forcoupling the storage medium to a device for reading and/or writing therecord carrier (1).
 5. A record carrier (1) as claimed in claim 4,characterized in that the second area (4.1, . . . , 4.8) is designed forcomprising a chip integrating the storage medium and the couplingelement of that second area (4.1, . . . , 4.8).
 6. A coupling elementbeing designed for being attached to a second area (4.1, . . . , 4.8) ofa record carrier (1) as claimed in claim
 1. 7. A carrier device, inparticular a plastic film, with a coupling element as claimed in claim6.
 8. A device for reading and/or writing a record carrier (1) asclaimed in claim 1, wherein the device is designed for sensing thedistribution of the coupling elements on the record carrier (1).
 9. Adevice for reading and/or writing as claimed in claim 8, characterizedin that the device is designed for accessing the first area (3) andsensing the distribution of the coupling elements on the record carrier(1) in parallel.
 10. A device for reading and/or writing as claimed inclaim 8, characterized in that the device is designed for decoding thethird kind of information being encoded in the distribution of thecoupling elements on the record carrier (1).
 11. A system for handlinginformation, in particular for supporting access control to information,the system comprising a device as claimed in claim 8 and a recordcarrier (1) as claimed in claim 1 carrying the information.
 12. A methodfor handling, in particular for reading and/or writing, a record carrier(1) as claimed in claim 1, with the steps: sensing and decoding thethird kind of information, and handling the record carrier (1) independence on the third kind of information, in particular, readingand/or writing all or part of the first kind of information independence on the third kind of information.